It is observed that wide frequency bands may be allocated to different systems, such as GSM and UMTS. In each of such systems smaller frequency subbands may be allocated to different telephone companies. Each of said subbands may contain several carriers or carrier signals having different carrier frequencies and being allocated to different parts of the premises or buildings where the method and system are applied.
Occasionally it may occur that a carrier signal interferes with a carrier signal transmitted by a source or antenna outside the present system. Further, one may want to expand the antenna network while using therein carrier signals having radio-frequency bands which may or may not differ from those already used or associated with different peripheral devices. Until now, to achieve this the coupling of carrier signals to the main transmission path required the application of a main coupling device designed and equipped to handle such expansion or the coupling device needed to be replaced by such more complex coupling device. When deploying carrier signals having radio-frequency bands which are in use already, the main coupling device must be designed to have a plurality of ports for connection to a plurality of cables of separate antenna networks accordingly. In fact the system of the type having one such port, as mentioned above, is just duplicated. A major drawback of modifying or replacing the coupling device is that at least part of the system is out of operation then. Another drawback is that equipment for deploying additional carrier signals must be installed in the proximity of the coupling device, which may be difficult or impossible to do because of limited space, cooling restrictions and higher power demands.